Imaging & Spectroscopy

Cloud Behaviour On Tidally Locked Rocky Planets From Global High-resolution Modeling

By Keith Cowing
Status Report
June 21, 2023
Filed under , , , , , , , ,
Cloud Behaviour On Tidally Locked Rocky Planets From Global High-resolution Modeling
Time-mean vertically-integrated cloud water amount (including both liquid and ice) simulated by the three models. Left panels are for TRAPPIST-1e, and right panels are for K2-72e. The global-mean values are listed in the top left corner of each panel. The red cross marks the substellar point. The blue dashed line is the morning terminator and the blue dotted line is the evening terminator, used for transmission spectra calculations (Fig. 6 below). SAM has less total cloud water path. — astro-ph.EP

Determining the behaviour of convection and clouds is one of the biggest challenges in our understanding of exoplanetary climates.

Given the lack of in situ observations, one of the most preferable approaches is to use cloud-resolving or cloud-permitting models (CPM). Here we present CPM simulations in a quasi-global domain with high spatial resolution (4×4 km grid) and explicit convection to study the cloud regime of 1 to 1 tidally locked rocky planets orbiting around low-mass stars.

We show that the substellar region is covered by deep convective clouds and cloud albedo increases with increasing stellar flux. The CPM produces relatively less cloud liquid water concentration, smaller cloud coverage, lower cloud albedo, and deeper H2O spectral features than previous general circulation model (GCM) simulations employing empirical convection and cloud parameterizations.

Furthermore, cloud streets–long bands of low-level clouds oriented nearly parallel to the direction of the mean boundary-layer winds–appear in the CPM and substantially affect energy balance and surface precipitation at a local level.

Jun Yang, Yixiao Zhang, Zuntao Fu, Mingyu Yan, Xinyi Song, Mengyu Wei, Jiachen Liu, Feng Ding, Zhihong Tan

Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:2306.12186 [astro-ph.EP] (or arXiv:2306.12186v1 [astro-ph.EP] for this version)
Submission history
From: Xinyi Song
[v1] Wed, 21 Jun 2023 11:33:06 UTC (17,033 KB)

Explorers Club Fellow, ex-NASA Space Station Payload manager/space biologist, Away Teams, Journalist, Lapsed climber, Synaesthete, Na’Vi-Jedi-Freman-Buddhist-mix, ASL, Devon Island and Everest Base Camp veteran, (he/him) 🖖🏻